1. Field of the Invention
The present invention relates to a peer to peer (P2P) type communication system including a plurality of node devices mutually communicable through a network.
2. Discussion of the Related Art
In radio broadcast utilizing the internet, when broadcast pages acquired from websites related to radio broadcast via a browser in a personal computer (hereinafter referred to as “PC”) are displayed, content data related to the radio broadcast are subjected to stream distribution to the PC.
On the other hand, a peer-to-peer type communication system has been recently featured as a new configuration instead of a server-client type which is the mainstream configuration in the current content distribution. A tree-type broadcast (distribution) system is for example in Japanese Unexamined Patent Publication No. 2006-33514. In this tree-type broadcast system, a plurality of node devices participating in the system form a plurality of hierarchy levels while placing a broadcast station (e.g. broadcast device) at a top of the hierarchy levels and connecting the hierarchy levels in a tree-like form via a communication means. Content data (e.g. image data and audio data) broadcasted (streamed) from the broadcast station are sequentially transferred (stream relay process) from node devices in higher hierarchy levels to node devices in lower hierarchy levels.